Marauding pirates could soon find themselves up against a new long-range laser weapon, designed to leave them blinded, bewildered and all at sea.

Although the laser will not necessarily repel determined aggressors, it should let them know that they have been spotted while still at a distance and that their quarry is ready for them.

"This is very much a non-lethal weapon," says Bryan Hore of BAE Systems in Farnborough, UK, where the system was developed. By taking into account the range of the target, as well as the atmospheric conditions, the system can automatically regulate the intensity of the laser beam to ensure there is no lasting eye damage, he says.

Sight for sore eyes

While the effects are not permanent, the light should leave pirates at least wishing they had worn an eyepatch or two: from as far away as 1500 metres the effect of looking at the beam is like accidentally looking at the sun, says Hore.

"Sunglasses wouldn't help," he says – in fact, wearing them would only exacerbate the effect. That's because the glasses would not affect the green laser light – chosen because that colour is particularly irritating – but the laser would appear even brighter contrasted against the darkened background.

"It's a warning shot," says Hore. "[The pirates] are looking for targets of opportunity," he says.

The metre-wide beam can target the entire vessel and its crew. "They tend to be 6-metre skiffs," says Hore, so the beam can be scanned across the entire vessel. This would make it difficult for the attackers to target their weapons, which are usually AK-47 assault rifles and rocket-propelled grenades, he says.Piratical practice

According to antipiracy organisation the International Maritime Bureau there were 430 pirate attacks last year, an increase of 5.6 per cent on the previous year. In a bid to develop a suitable non-lethal weapon to help fend off this threat, BAE Systems studied pirate behaviour. The conclusion, says Hore, was that an automatic weapon was needed, one that would not put any of the crew at risk, and one which would distract suspected pirates rather than harm them.